DE69811998T2 - Process for applying a protective and decorative coating to an object - Google Patents

Description

Field of the Invention

The present invention is based on a process for applying protective and decorative coatings on objects directed, in particular to a method for applying a multilayer Coating on at least a portion of an object surface according to the preamble of claim 1.

background the invention

The provision of an item such as a brass faucet or lock with one multilayer coating by applying a first coating layer or Series of coating layers by electroplating and then applying a second coating layer or series of coating layers on the electroplated coating layer by physical In the prior art, vapor deposition is, for example, off known document EP-A-0 297 830 which describes the preamble of the claim 1 forms. Such a multilayer coating creates one Abrasion and corrosion protection for the object, is decorative, and compensates for defects such as nicks and Scratch off the item. For example, a brass object which is a double layer of nickel, made of bare nickel and on this galvanically applied semi-bright nickel, and has a zirconium nitride layer by physical vapor deposition applied to the double nickel layer, smooth, has one improved resistance to abrasion and corrosion and has the color of polished brass.

It is generally by vapor deposition manufactured layer, which protects against abrasion and the decorative Provides appearance. The one produced by vapor deposition Coating layer is generally quite thin, typically in the range of approximately 0.0254 µm up to 0.508 μm [one to 20 millionths of an inch]. Because of the thinness of by vapor deposition manufactured coating seems every water stain or everyone other surface defect such as nickel or chrome stains caused by the electroplating process originate from or were caused by this and are in the Act through the thin, coating produced by vapor deposition is emphasized. Self Dots, stains or discoloration, which on the galvanized object is not visible to the naked eye are visible after the one produced by vapor deposition Coating is applied.

Therefore, it is currently necessary every item completely to examine, clean and dry when it comes out of the galvanic Bathroom comes out. A conventional one The way of cleaning the galvanized objects is things run through a water based cleaning system and use nitrogen drying to dry the items. This is quite expensive and not always successful. Another Procedure involves drying and cleaning by hand each single item. This hand drying is, although it is more effective as a nitrogen-based drying system is very labor intensive and therefore pretty expensive too. Hand drying also includes Handling the galvanized objects, what a dropping or Bump of objects against other objects with resulting damage the objects for Result can have.

It would be very beneficial if one efficient and effective drying process for the galvanized articles would be available, which with conventional, currently problems associated with the cleaning and drying processes used. It is an object of the present invention to provide such a system to accomplish.

Summary the invention

The above task is accomplished by the Features specified in claim 1 solved. Advantageously developed embodiments are subject to the dependent Expectations 2 to 14.

The present invention includes a method for applying a multi-layer protective and decorative coating on an object. The process involves applying first of at least one coating layer by electroplating. The galvanized object is then removed from the galvanic bath and subjected to pulse blow drying for spot-free drying. The dried galvanized article is then placed in a vapor deposition chamber placed and further coating layers are by vapor deposition (vapor deposition) applied to the galvanized object.

Electroplating involves the application of at least one layer made of copper, nickel and chrome. The galvanic copper plating includes both the alkaline copper plating and the acid copper plating. The galvanic nickel plating includes the plating of bright nickel, semi-bare nickel, and a double layer of nickel made of bare Nickel and semi-bright nickel.

Before the galvanized article is subjected to a gas phase deposition process in order to apply thin coating layers on the electroplated coating by gas phase deposition, the article is in the Pulse blow dried to remove any wet stains or nickel or chrome stains.

After the pulse blow drying Coating layers by physical vapor deposition applied to the top electroplated layer. The layers applied by vapor deposition are turned into base, heat resistant Metals and base, heat-resistant Metal alloys and from base, heat-resistant Metal connections and connections of base, heat-resistant metal alloys selected. The base, heat-resistant Metal connections and the connections of base, heat-resistant metal alloys contain the nitrides, oxides, carbides, carbonitrides and reaction products one heat-resistant Metal or a heat-resistant Metal alloy, oxygen and nitrogen.

Short description of the drawings

1 Fig. 3 is a cutaway perspective view of a pulse blow dryer;

2 Fig. 4 is an out-of-scale sectional view of a portion of the substrate on which the electroplated coating layers are located;

3 is similar to a view 2 , but which shows another embodiment of the invention with a different arrangement of the electroplated coating layers;

4 Fig. 4 is an out-of-scale sectional view showing an arrangement of layers made by physical vapor deposition;

5 is similar to a view 4 which, however, shows another embodiment of the invention with a different arrangement of different layers produced by physical vapor deposition; and

6 Fig. 4 is an out-of-scale sectional view of a portion of the substrate on which the electroplated and physical vapor deposition coating layers are located.

description of the preferred embodiment

The method of this invention is especially by creating a decorative and protective, thin coating layer produced by vapor deposition a galvanically produced lower layer, which free of defects and imperfections such as water stains, nickel stains and is chrome stains. These shortcomings and imperfections generally occur due to stains, which as a result of the galvanizing process on the galvanized surface of the object remain. If the thin, by vapor deposition produced coating layer applied to these stains this thin, coating layer produced by physical vapor deposition very much emphasized.

The method of the present invention comprises first the application of at least one electroplated coating layer on at least a portion of the surface of an object that Remove the galvanized object from the galvanic bath and subjecting the item to pulse blow drying to remove any stains from its surface, and applying from thin Coating layers using physical vapor deposition on the clean and dry galvanized surface.

Pulse blow drying and a pulse blow dryer are described in European Patent 0 486 711. The pulse blow dryer is in 1 illustrated. In short, it has a housing similar to a conventional and well-known circulation air dryer. Fan, heating device and air circulation flaps correspond to known and conventional designs. A movable nozzle device is also installed on each side of the station. The nozzle device is equipped with small nozzle tubes, approximately 150 mm long, and is provided with 15 bores which correspond to the width of the direction of movement. Each small nozzle pipe is supplied with air with the help of solenoid valves. The solenoid valves are controlled by a microprocessor, which allows the valves to be opened one by one. The opening intervals can be set to between 20 and 100 ms via the control device. In the case of wide dryers, the valves are opened in groups, ie 6–8 small nozzle pipes, with one pipe always open. The nozzle devices are moved up and down in the opposite direction at an adjustable speed. The speed is usually about one to two strokes per minute. The stroke corresponds to the height of the frame plus 50 mm above and below.

The impulse-like connection of the individual small nozzle pipes to the compressed air supply with a nominal pressure of six bar results in 15 air jets / pipe. These air jets atomize the water droplets on the surface of the parts. Due to the repeated blowing of the surface of the objects with the pulsating air jets and the progression from nozzle tube to nozzle tube in the horizontal position, an air flow is generated for approximately 1 cm ^{2 of} the surface.

The alternating sweeping and blowing of the sharp air jets into bores, blind holes, undercuts and edges leads to a suction effect, which even exhausts the liquid the cavities removed. This effect is so strong that even long holes in hollow parts, large interiors and threaded holes are dried well. When the parts are removed from the racks, no water flows out of the cavities and therefore the quality of the surface is not spoiled by water stains.

A programmable control device allows preselection of the pulse frequency, the speed of the Nozzle means, the number of open at the same time Valves, the number of strokes and the temperature. These parameters can be assigned to the objects to be treated. In a drying program, the speed and the pulse frequency for every stroke can be set individually. Size Items with a big one Length can be in can be blown off very quickly with short air pulses after the first stroke. The majority of the adhering water droplets are blown away here.

While of the following strokes the speed is automatically reduced and the pulse frequency will be extended. The stronger ones Air impulses and those for a longer one Permanently open Valves have a significantly better suction effect, which in one improved drying of the cavities results.

When the bulk of the water is blown away, d. H. atomized only a very thin one remains drying adsorption layer. Therefore, only short drying times from two to five Minutes at a circulating air temperature of 50–70 ° C.

The impulse blow drying is one spotless drying ready. Thus it can be used on galvanized objects without a further cleaning or drying of the galvanized objects Physical vapor deposition produced thin coating be applied.

The item can be made from any plattable Substrate such as metal or plastic. The metals which the item can consist of include brass, zinc, Steel and aluminum. The electroplated coating, which by electroplating on at least a portion of the surface of the Item applied can be a layer or more than one Layer. Preferred electroplated coatings include copper, including alkaline copper and acid copper, Nickel, including bare nickel and semi-bare nickel, and chrome.

If the item is made of brass, be typically at least one nickel layer and one chrome layer applied by galvanizing to the object, the nickel layer directly on the surface the object is applied and the chrome layer on the nickel layer is applied. Brass objects can also have a copper layer that is applied directly to their surface becomes. Then at least one layer of nickel is plated applied to the copper layer. A chrome layer is then through Electroplating applied to the nickel layer.

The nickel layer is made by conventional and well-known electroplating process on at least a portion of the surface of the substrate object applied. These procedures include the use of a conventional galvanic bath, such as Example of a Watts bath as the plating solution. Typically contain such Baths in Water dissolved Nickel sulfate, nickel chloride and boric acid. All chloride, sulfamate and and fluoroborate plating solutions are used become. These baths can optionally a number of known and conventionally used compounds such as leveling agents, brighteners and the like. To one Generating mirror-bright nickel layer is at least the plating solution a class I brightener and at least one brightener from Class II added. Class I brighteners are organic compounds that contain sulfur. Class II brighteners are organic Compounds that do not contain sulfur. Class brightener II can also cause leveling and, if without the galvanic bath the class I sulfur-containing brightener is added, lead to semi-bare nickel deposits. This gloss agent of Class I include alkyl naphthalenes and benzenesulfonic acids Benzene and naphthalene di- and trisulfonic acids, benzene and naphthalene sulfonamides as well as sulfonamides such as saccharin, vinyl and allyl sulfonamides and Sulfonic acids. Class II brighteners are generally unsaturated organic Substances such as acetylene or ethylene alcohols, ethoxylated and propoxylated acetylene alcohols, coumarins and aldehydes. This Class I and class II gloss agents are known to those skilled in the art and easily available in stores. They are among others in the US patent No. 4,421,611.

The nickel layer can be a monolithic layer be made of, for example, semi-bright nickel or bright nickel consists; or it can be a double layer, the one layer made of semi-bare nickel and one made of bare nickel contains existing layer. The thickness of the nickel layer is generally in the range of approximately 2.54 µm [100 millionths (0.000100) inch], preferably about 3.81 µm [150 millionths (0.000150) inches] to approximately 88.9 µm [3,500 millionths (0.0035) inches].

As is well known in the art is the substrate before the nickel layer on the substrate is subjected to activation by placing it in a conventional one and well-known acid bath gives.

With one in the 2 illustrated embodiment, the nickel layer 13 did essentially from two different nickel layers 14 and 16 , The layer 14 consists of semi-bright nickel, while the layer 16 is made of bare nickel. This double nickel coating provides improved corrosion protection for the underlying substrate. The semi-bare, sulfur-free coating 14 using a conventional galvanizing process directly on the surface of the substrate 12 applied. The substrate 12 with the half-bare nickel layer 14 is then immersed in a galvanic bath with bare nickel and the bare nickel layer 16 is on the semi-bare nickel layer 14 applied.

The thickness of the half-bare nickel layer and the bare nickel layer is such that it ensures improved protection against corrosion. Generally, the thickness of the semi-bare nickel layer is at least about 1.27 µm [50 millionth (0.00005) inches], preferably at least about 2.54 µm [100 millionth (0.0001) inches], and more preferably at least about 3, 81 µm [150 millionths (0.00015) inches]. The upper limit of thickness is generally not critical and depends on considerations such as cost. In general, however, a thickness of about 38.1 µm [1,500 millionth (0.0015) inches], preferably about 25.4 µm [1,000 millionth (0.001) inches], and more preferably about 19.05 µm [750 millionth (0 , 00075) inches] must not be exceeded. The bare nickel layer 16 generally has a thickness of at least about 1.27 µm [50 millionths (0.00005) inches], preferably at least about 3.175 µm [125 millionths ( 0 , 000125) inches], and more preferably at least about 6.35 µm [250 millionths (0.00025) inches]. The upper limit of the thickness of the bare nickel layer is not critical and is generally dependent on considerations such as cost. In general, however, a thickness of about 63.5 µm [2,500 millionth (0.0025) inches], preferably about 50.8 µm [2,000 millionths (0.002) inches], and more preferably about 38.1 µm [1,500 millionths (0th , 0015) inch] must not be exceeded. The bare nickel layer 16 also fulfills the function of a leveling layer that can cover or fill in imperfections in the substrate.

In another embodiment of the invention, as in 2 is a chrome layer 20 in a galvanic way on the nickel layer 13 applied. The chrome layer 20 can by means of conventional and known chrome electroplating techniques on the nickel layer 13 be applied. These techniques and various chrome plating baths are disclosed in: Brassard, "Decorative Electroplating - A Process in Transition", Metal Finishing, pp. 105-108, June 1988; Zaki, "Chromium Plating," PF Directory, pp. 146-160; and in U.S. Patent Nos. 4,460,438, 4,234,396 and 4,093,522.

Chromium plating baths are well known and commercially available. A typical chrome plating bath contains chromic acid or salts thereof and a catalyst ion such as sulfur or fluoride. The catalyst ions can be provided by sulfuric acid or its salts and silicon hydrofluoric acid. The baths can be maintained at a temperature of 44.4-46.6 ° C [112-116 ° F]. Typically, chrome plating uses a current density of approximately 1615 A / m ² [150 amps per square foot] at approximately 5 to 9 volts.

The chrome layer generally has a thickness of at least about 0.051 µm [2 millionths (0.000002) inches], preferably at least about 0.127 µm [5 millionths (0.000005) inches], and more preferably at least about 0.203 µm [8 millionths ( 0 , 000008) inches]. The upper limit of thickness is generally not critical and depends on considerations such as cost. In general, however, the thickness of the chrome layer should be about 1.524 µm [60 millionth (0.00006) inches], preferably about 1.27 µm [50 millionths (0.00005) inches], and more preferably about 1.016 µm [40 millionths (0.0 00004) inch].

In another embodiment of the invention, as in 3 is illustrated, in particular when the substrate object consists of zinc or brass, a copper layer in a galvanic manner 17 or layers on at least a portion of the article surface 12 applied. The nickel layer 16 is then electroplated onto the copper, followed by electroplating of chrome 20 on the nickel layer. The nickel layer can be a monolithic layer, as in 3 is illustrated, and consist for example of bare nickel, or it can be a double nickel layer, which consists for example of a bare nickel layer and a semi-bare nickel layer. The copper coating 17 can consist of a monolithic copper layer or two different copper layers, for example an alkaline copper layer on the surface of the article and an acidic copper layer on the alkaline copper layer. At the in 3 The exemplary embodiment illustrated is the copper coating 17 a monolithic copper layer made of acidic copper.

Copper plating processes and copper plating baths are conventional available and well known in the art. They involve electroplating of acidic copper and alkaline copper. You will among other things in the U.S. Patents No. 3,725,220; 3,769,179; 3,923,613; 4,242,181 and 4,877,450.

The preferred copper layer is selected from alkaline copper and acid copper. The copper layer can be monolithic and made of a type of copper, such as alkali cal copper or acid copper, or it may have two different layers of copper, such as one made of alkaline copper 11a existing layer and one of acidic copper 11b existing layer.

The thickness of the copper layer is generally in the range of at least about 2.54 µm [100 millionths (0.0001) Inch], preferably at least about 3.81 µm [150 millionths (0.00015) inches] until about 88.9 µm [3,500 millionths (0.0035) inches], preferably about 50.8 µm [2,000 Millionths (0.002) inches].

If a double layer of copper is present, for example from an alkaline copper layer and there is an acidic copper layer, the thickness of the alkaline Copper layer generally at least about 1.27 μm [50 millionths (0.00005) Inch], preferably at least about 1.905 μm [75 millionths (0.000075) Inch]. The upper limit of the thickness is generally not critical. Generally, a thickness of approximately 38.1 µm [1,500 millionths (0.0015) Inch], preferably 25.4 µm [1,000 millionths (0.001) inches] should not be exceeded. The fat the acidic copper layer generally at least approximately 12.7 µm [50 Millionths (0.0005) inches], preferably at least about 19.05 µm [75 millionths (0.00075) inches]. The upper limit of the thickness is generally not critical. Generally, a thickness of approximately 38.1 µm [1,500 Millionths (0.0015) inches], preferably 25.4 µm [1,000 millionths (0.001) Inch] not exceeded become.

Some illustrative, not restrictive examples for electroplated layers include substrate / nickel such as Example bare nickel / chrome, substrate / semi-bare nickel / bare Nickel / chrome, substrate / nickel such as bare nickel, substrate / semi-bright Nickel / bare nickel, substrate / copper such as acid copper / Nickel such as bare nickel / chrome, substrate / alkaline Copper / nickel such as bare nickel / chrome, substrate / copper such as alkaline copper / semi-bright nickel / bright nickel / chrome, Substrate / alkaline copper / acid copper / semi-bare nickel / bare Nickel / chrome, substrate / copper such as acidic copper / nickel such as bare nickel, substrate / copper such as alkaline copper / semi-bright nickel / bright nickel, and substrate / alkaline Copper / acid copper / semi-bare nickel / bare nickel.

After the article has received the various electroplated coating layers, as before and in the 2 and 3 that were applied to it by electroplating, it is then subjected to pulse blow drying to blow off any spots, stains, moisture or droplets and to produce a galvanized article that has a stain-free surface. After the pulse blow drying is complete, the galvanized article is placed in a chamber for physical vapor deposition, and thin layers of coating are applied to the surface of the galvanized article by physical vapor deposition.

The layers, which by physical vapor deposition are applied, are metallic layers and are made of base, heat-resistant Metals, base, heat-resistant metal alloys, base, heat-resistant Metal connections and connections of base, heat-resistant metal alloys selected. The base, heat-resistant Metals include hafnium, tantalum, titanium and zirconium. The preferred heat-resistant Metals are titanium and zirconium, with zirconium being more preferred is. The base, heat-resistant Metal alloys include the alloys of the foregoing heat-resistant Metals, being the binary Alloys are preferred. The preferred binary alloys are the binary alloys of zirconium, being the binary Alloys of zirconium and titanium are more preferred.

The connections of the base, heat-resistant metals and metal alloys include the nitrides, oxides, and carbides Carbonitrides of base, heat-resistant metals and metal alloys. Also includes in the Compounds of base, heat-resistant metals and metal alloys that useful in the present invention are the reaction products of a base, heat-resistant metal or metal alloy, oxygen and nitrogen. Examples of this base, heat-resistant Metal compounds include zirconium nitride, zirconium oxide, zirconium carbide, Zirconium carbonitride, reaction products of zirconium, oxygen and Nitrogen, titanium nitride, titanium oxide, titanium carbonitride, reaction products of titanium, oxygen and nitrogen, hafnium nitride, hafnium oxide, Hafnium carbonitride, tantalum oxide, tantalum nitride, tantalum carbide and the like.

The reaction products of a base, heat-resistant Metals such as zirconium, oxygen and nitrogen Zirconium oxide, zirconium nitride and zirconium oxynitride.

Some illustrative, not restrictive Examples of the connections of base, heat-resistant metal alloys include Zirconium titanium nitride, zirconium titanium oxide, zirconium titanium carbide, zirconium titanium carbonitride, Hafnium-zirconium nitride, Hafnium tantalum oxide, tantalum titanium carbide and reaction products one Zirconium-titanium alloy, oxygen and nitrogen.

The layers of refractory metals and refractory metal alloys are applied to at least a portion of the surface of the galvanized article by conventional and well known physical vapor deposition techniques such as ion sputtering applied by cathodic arc electron evaporation beam deposition and the like. The techniques and equipment of ion sputtering are described, inter alia, in: T. Van Vorous, "Planar Magnetron Sputtering; A New Industrial Coating Technique", Solid State Technology, Dec. 1976, pp. 62-66; U. Kapacz and S. Schulz, "Industrial Application of Decorative Coatings - Principle and Advantages of the Sputter Ion Plating Process", Soc. Vac. Coat., Proc. 34. Arn. Tech. Conf., Philadelphia, USA, 1991, 48-61; J. Vossen and W. Kern "Thin Film Processes II", Academic Press, 1991; R. Boxman et al., "Handbook of Vacuum Arc Science and Technology", Noyes Pub., 1995; and U.S. Patent Nos. 4,162,954 and 4,591,418.

In short, the sputtering process is one heat-resistant Metal such as a titanium or zirconium target, which is the cathode and the substrate is placed in a vacuum chamber. The Air in the chamber is drawn off to create vacuum conditions in the chamber. An inert gas such as argon is introduced into the chamber. The gas particles are ionized and accelerated to the target, to remove titanium or zirconium atoms. The detached target material is then typically applied as a coating film on the substrate deposited.

When arc sputtering hits an electrical arc typically of several hundred amperes on the surface a metal cathode such as zirconium or titanium. The arc atomized the cathode material, which then deposits on the substrates and a Coating forms.

The reactive ion sputtering process generally corresponds to the ion sputtering process, except for that a reactive gas such as oxygen or nitrogen in the Chamber is initiated, which reacts with the detached target material. Thus, in the case where zirconium nitride forms a layer, the target is made of zirconium and nitrogen is the one introduced into the chamber reactive gas. By adjusting the amount of nitrogen which available To react with the zirconium, the color of the zirconium nitride can be changed of brass in different shades.

Generally, more than one Layer made of a heat-resistant Metal, a heat-resistant Metal alloy, a heat-resistant metal compound and a connection of a heat-resistant Metal alloy is applied to the galvanized object. For example, a layer made of heat-resistant metal or a heat-resistant one Metal alloy such as zirconium, by means of gas phase deposition applied to the galvanized object; then a sandwich layer, which consist of alternating layers of heat-resistant metal or a heat-resistant metal alloy for example zirconium and heat-resistant metal compound or a connection of a heat-resistant Metal alloy such as zirconium nitride is made on the Zirconium layer applied; and a layer made up of the reaction products one heat-resistant Metal or a heat-resistant Metal alloy such as zirconium, oxygen and nitrogen exists, is applied to the sandwich layer.

In another embodiment becomes a layer made of a first heat-resistant metal compound or connection of a heat-resistant Metal alloy, preferably a nitride, by means of gas phase deposition on the layer of a heat-resistant metal or a heat-resistant metal alloy applied. Then one layer is made up of another second heat-resistant Metal connection or connection of a heat-resistant metal alloy, preferably an oxide or the reaction products of a refractory metal or a heat-resistant one Metal alloy, Oxygen and nitrogen exist by means of vapor deposition on the layer consisting of a heat-resistant metal compound or Connection of a heat-resistant Metal alloy applied.

Generally, the layer of a refractory metal or metal alloy has a thickness of at least about 0.00635 µm [0.25 millionth (0.00000025) inches], preferably at least about 0.0127 µm [0.5 millionth ( 0.0000005) inch], and more preferably at least about 0.0254 µm [one millionth (0.000001) inch]. The upper limit of thickness is not critical and is generally dependent on considerations such as cost. In general, however, the layer consisting of a heat-resistant metal or a heat-resistant metal alloy should not be thicker than approximately 1.27 μm [50 millionths (0.1 00005 ) Inch], preferably about 0.381 µm [15 millionth (0.000015) inch], and more preferably about 0.254 µm [10 millionth (0.000010) inch].

In general, the layer consisting of a heat-resistant metal or a heat-resistant metal alloy serves, among other things, for the adhesion of a layer consisting of a heat-resistant metal compound, a compound of a heat-resistant metal alloy, reaction products of a heat-resistant metal or a heat-resistant metal Alloy, oxygen and nitrogen exist to improve on the galvanized object. For example, the layer of a heat-resistant metal or metal alloy generally has a thickness that is at least effective to ensure the adhesion of a layer made of a heat-resistant metal compound, a compound of a heat-resistant metal alloy, and reaction products of a heat-resistant metal or a heat-resistant metal Le alloy, oxygen and nitrogen exist to improve on the galvanized object.

In a preferred embodiment of the In the present invention, the layer is made of refractory metal made of zirconium, titanium or a zirconium-titanium alloy, preferably Zirconium or a zirconium-titanium alloy, and is by means of physical vapor deposition processes such as Ion sputtering or electron beam evaporation applied.

The layer consisting of a heat-resistant metal compound, a compound of a heat-resistant metal alloy or reaction products of a heat-resistant metal or a compound of a heat-resistant metal alloy, oxygen and nitrogen generally has a thickness which is at least about 0.0508 μm [2 millionths (0.000002) inches], preferably at least about 0.1016 µm [4 millionths (0.000004) inches], and more preferably at least about 0.1524 µm [6 millionths (0.000006) inches]. The upper limit of thickness is generally not critical and is dependent on considerations such as cost. In general, a thickness of approximately 0.762 μm [30 millionths (0.1 00003 ) Inches], preferably about 0.635 µm [25 millionths (0.000025) inches], and more preferably about 0.508 µm [20 millionths (0.000020) inches].

This layer generally provides for wear resistance, Abrasion resistance and the desired Color or the one you want Appearance. This layer is preferably made of zirconium nitride or a nitride of a zirconium-titanium alloy, which is the color of brass. The thickness of this layer is at least effective wear resistance, Abrasion resistance and the desired color or the one you want Provide appearance.

In another embodiment of the invention, a sandwich layer consisting of alternating layers of a base, heat-resistant metal compound or a connection of a base, heat-resistant metal alloy and a base, heat-resistant metal or a base, heat-resistant metal alloy is applied the layer of a heat-resistant metal or a heat-resistant metal alloy such as zirconium or a zirconium-titanium alloy. An exemplary structure of this embodiment is shown in 4 22 in which 22 represents the layer of refractory metal or a refractory metal alloy, preferably zirconium or a zirconium-titanium alloy, 26 represents the sandwich layer, 28 represents a layer of a base, refractory metal compound or a compound of one represents a base, heat-resistant metal alloy, and 30 represents a layer of base, heat-resistant metal or a base, heat-resistant metal alloy.

The base, heat-resistant metals and the base, heat-resistant metal alloys that make up the layers 30 include hafnium, tantalum, titanium, zirconium, zirconium-titanium alloy, zirconium-hafnium alloy and the like; preferably zirconium, titanium or zirconium-titanium alloy; and more preferably zirconium or zirconium-titanium alloy.

The base, heat-resistant metal connections and the connections of base, heat-resistant metal alloys that make up the layers 28 include hafnium compounds, tantalum compounds, titanium compounds, zirconium compounds and zirconium-titanium alloy compounds; preferably titanium compounds, zirconium compounds or compounds of a zirconium-titanium alloy; and more preferably zirconium compounds or zirconium-titanium alloy compounds.

These compounds are made from nitride, Carbides and carbonitrides selected, the nitride preferred is. So the titanium compound from titanium nitrides, titanium carbides and titanium carbonitrides selected, the titanium nitride is preferred. The zirconium compound will selected from zirconium nitride, zirconium carbide and zirconium carbonitride, the Zirconium nitride is preferred.

The sandwich layer 26 generally has an average thickness of from about 1.27 µm [50 millionth (0.00005) inches] to about 0.0254 µm [one millionth (0.000001 inch]], preferably from about 1.016 µm [40 millionth (0.00004 ) Inches] to about 0.0508 µm [two millionths (0.000002) inches], and more preferably from about 0.762 µm [30 millionths (0.00003) inches] to about 0.0762 µm [three millionths (0.000003 ) Inch].

Each of the layers 28 and 30 generally has a thickness of at least about 0.000508 µm [0.002 millionth (0.00000002) inches], preferably at least about 0.00254 µm [0.1 millionth (0.0000001) inches], and more preferably at least about 0.0127 µm [0.5 millionth (0.0000005) inches]. In general, the layers 28 and 30 not be thicker than about 0.635 µm [25 millionth (0.000025) inches], preferably about 0.254 µm [10 millionth (0.00001) inches], and more preferably about 0.127 µm [5 millionth (0.000005) inches].

A method of forming the sandwich layer 26 provides for the use of ion sputter coating to coat one layer 30 from a base, heat-resistant metal such as zirconium or titanium, followed by a reactive ion sputter coating to coat one layer 28 from a base, heat-resistant metal nitride such as zirconium nitride or titanium nitride.

Preferably, the flow rate of the nitrogen gas during reactive ion sputter coating is varied between zero (no nitrogen gas is introduced) and the introduction of nitrogen in the desired amount (pulsed) by several alternating layers of metal 30 and metal nitride 28 in the sandwich layer 26 train.

The number of alternating layers of a heat-resistant metal 30 and the layers 28 made of a heat-resistant metal compound in the sandwich layer 26 is generally at least about two, preferably at least about four, and more preferably at least about six. In general, the number of alternating layers should be made of a refractory metal 30 and a heat-resistant metal connection 30 in the sandwich layer 26 not exceed about 50, preferably about 40 and more preferably about 30.

In one embodiment of the invention, as in 4 is illustrated on the sandwich layer 26 a layer 32 , consisting of a base, heat-resistant metal compound or a connection of a base, heat-resistant metal alloy, preferably a nitride, carbide or carbonitride, and more preferably a nitride, applied by vapor deposition.

The layer 32 consists of a hafnium compound, a tantalum compound, a titanium compound, a compound of a zirconium-titanium alloy or a zirconium compound, preferably a titanium compound, a compound of a zirconium-titanium alloy or a zirconium compound , and more preferably a zirconium compound or a zirconium-titanium alloy compound. The titanium compound is selected from titanium nitride, titanium carbide and titanium carbonitride, with the titanium nitride being preferred. The zirconium compound is selected from zirconium nitride, zirconium carbonitride and zirconium carbide, with the zirconium nitride being preferred.

The layer 32 provides wear and abrasion resistance as well as the desired color or appearance, such as bare brass. The layer 32 will on the layer 26 applied using a well known and conventional physical vapor deposition process such as reactive ion sputtering.

The layer 32 has a thickness that is at least effective to create the abrasion resistance and / or the color of brass. Generally, this thickness is at least 0.0508 µm [2 millionths (0.000002) inches], preferably at least 0.1016 µm [4 millionths (0.000004) inches], and more preferably at least 0.1524 µm [6 millionths (0th , 000006) inches]. The upper limit of thickness is generally not critical and depends on considerations such as cost. Generally, however, a thickness should be about 0.762 µm [30 millionths (0.00003) inches], preferably about 0.635 µm [25 millionths (0.000025) inches], and more preferably about 0.508 µm [20 millionths (0.000020) inches] ] are not exceeded.

Zirconium nitride is the preferred Coating material because it looks like polished brass the next comes.

In one embodiment of the invention, as in 4 is illustrated on the layer 32 a layer 34 applied, which consists of the reaction products of a base, heat-resistant metal or metal alloy, an oxygen-containing gas such as oxygen and nitrogen. The metals which can be used in the practice of this invention are those which are capable of forming both a metal oxide and a metal nitride under suitable conditions, for example using a reactive gas consisting of oxygen and nitrogen. The metals can be, for example, tantalum, hafnium, zirconium, a zirconium-titanium alloy and titanium, preferably titanium, a zirconium-titanium alloy and zirconium, and more preferably zirconium and a zirconium-titanium alloy.

The reaction products from the metal or the metal alloy, oxygen and nitrogen consist in generally from the metal or metal alloy oxide, the metal or metal alloy nitride and the metal or metal alloy oxynitride. So exist at Example the reaction products of zirconium, oxygen and nitrogen made of zirconium oxide, zirconium nitride and zirconium oxynitride.

The layer 34 can be applied using a well known and conventional physical gas phase coating technique, including reactive ion sputtering of a pure metal target and a gas or composite target of oxides, nitrides and / or metals.

These metal oxides and metal nitrides, comprising zirconium oxide and Zirconium nitride alloys, and their preparation and coating are conventional and well known and are described, among others, in U.S. Patent No. 5,367,285 disclosed.

The layer containing the metal, oxygen and nitrogen reaction products 34 generally has a thickness of at least about 0.00254 µm [0.1 millionth (0.0000001 inch)], preferably at least about 0.00381 µm [0.15 millionth (0.00000015) inch], and more preferably at least about 0.00508 µm [0.2 millionth (0.0000002) inches] In general, the metal oxynitride layer should not be thicker than about 0.0254 µm [one millionth (0.000001) inches], preferably about 0.0127 µm [ 0.5 millionth (0.0000005) inch], and more preferably about 0.01016 µm [0.4 millionth (0.0000004) inch].

In another embodiment, as in 5 is illustrated instead of the layer 34 , which consists of the reaction products of a heat-resistant metal or a heat-resistant metal alloy, oxygen and nitrogen, which on the layer 32 is applied a layer 36 , which consists of a base heat-resistant metal oxide or an oxide of a heat-resistant metal alloy, by means of physical vapor deposition on the layer 32 applied. The heat-resistant metal oxides and the oxides of heat-resistant metal alloys that make up the layer 36 , include, but are, hafnium oxide, tantalum oxide, zirconium oxide, titanium oxide and a zirconium-titanium alloy oxide, preferably titanium oxide, zirconium oxide and a zirconium-titanium alloy oxide, and more preferably zirconium oxide and a zirconium-titanium alloy oxide not limited to this.

The layer 36 has a thickness of at least about 0.00254 µm [0.1 millionth (0.0000001 inch)], preferably at least about 0.00381 µm [0.15 millionth (0.00000015) inch], and more preferably at least about 0, 00508 µm [0.2 millionth (0.0000002) inches]. In general, the layer should be made of metal or metal alloy oxide 36 not thicker than about 0.0508 µm [2 millionths (0.000002) inches], preferably about 0.0381 µm [1.5 millionths (0.0000015) inches], and more preferably about 0.0254 µm [one millionths (0th , 000001) inch].

6 illustrates an article substrate 12 , which is a bare nickel layer electroplated on its surface 16 and a chrome layer 20 has the galvanic on the bare nickel layer 16 is applied. The electroplated chromium layer is deposited by physical vapor deposition after the substrate object 12 with the layers electroplated on it 16 and 20 has undergone pulse blow drying, one layer 22 consisting of zirconium, a sandwich layer 26 , consisting of alternating layers 28 and 30 , which consist of zirconium nitride or zirconium, one layer 32 consisting of zirconium nitride, and a layer 34 consisting of the reaction products of zirconium, oxygen and nitrogen applied.

The following example is intended to better understanding serve the invention. The example is for illustration and restricts the invention does not.

example 1

Brass taps are immersed in a conventional cleaning bath containing the usual and well-known soaps, detergents, care products and the like for about 10 minutes and at a pH of 8.9-9.2 and a temperature of 82.2- 93.3 ° C [180-200 ° F] is maintained. The brass taps are then placed in a conventional alkaline ultrasonic cleaning bath. The ultrasonic cleaning bath has a pH of 8.9-9.2, is maintained at a temperature of approximately 71.1-82.2 ° C [160-180 ° F] and contains the usual and well-known soaps, Detergents, care products and the like. After ultrasonic cleaning, the taps are rinsed off and immersed in a conventional alkaline electric cleaning bath. The electro cleaning bath is maintained at a temperature of approximately 60-82.2 ° C [140-180 ° F] at a pH of approximately 10.5-11.5 and contains normal and conventional cleaning agents. The taps are then rinsed twice and placed in a conventional acid-activating bath. The acid activating bath has a pH of approximately 2.0-3.0, is at room temperature and contains an acidic salt based on sodium fluoride. The taps are then rinsed twice and placed in a galvanic bath with bare nickel for approximately 12 minutes. The bare nickel bath is generally a conventional bath which is maintained at a temperature of approximately 54.4-65.5 ° C [130-150 ° F] at a pH of approximately 4.0 and NiSO ₄ , Contains NiCL ₂ , boric acid and brightener. A bare nickel layer with an average thickness of approximately 10.16 µm [400 millionths (0.0004) inches] is applied to the surface of the tap. The faucets coated with bare nickel are rinsed three times and then placed in a conventional, commercially available hexavalent chrome plating bath using conventional chrome plating equipment for approximately seven minutes. The hexavalent chrome bath is a conventional and well known bath containing approximately 240 g / L [32 ounces / gallon] chromic acid. The bath also contains the conventional and well known chrome plating additives. The bath is maintained at a temperature of approximately 44.4-46.6 ° C [112-116 ° F] and uses a mixed sulfate / fluoride catalyst. The ratio of chromic acid to sulfate is approximately 200: 1. A chromium layer approximately 0.254 µm [10 millionths (0.00001) inches] thick is applied to the surface of the bare nickel layer. The taps are rinsed thoroughly in deionized water.

The galvanized taps are placed on a frame and the frame moves through a pulse blow dryer, manufactured by LPW-Anlagen GmbH, Germany, and described in the European patent application EP 0 486 711 A1 , The blow dryer is equipped with a series of small nozzles which emit pulsating air jets at 0.55 N / mm ² [80 psi]. The dryer is maintained at a temperature of 54.4 ° C [130 ° F]. The galvanized taps stay in the impulse blow dryer for a total of 210 seconds, whereby the rack moves two feet in five seconds. The frame remains motionless for 37 seconds and then advances again. The pulses last for about 20 milliseconds. The taps are removed from the pulse blow dryer and placed in a coating container to carry out the arc sputtering process. The container is generally a cylindrical housing which contains a vacuum chamber which is adapted to be evacuated by means of pumps. An argon gas source is connected to the chamber via an adjustable valve which is used to change the flow rate of argon into the chamber. In addition, a nitrogen gas source is connected to the chamber via an adjustable valve which serves to change the flow rate of nitrogen into the chamber.

A cylindrical cathode is in mounted in the middle of the chamber and to negative outputs one adjustable DC power supply unit connected. The positive side of the power supply unit is on the chamber wall connected. The cathode material contains zirconium.

The coated taps will be mounted on spindles, 16 of which are on a ring around the outside mounted around the cathode. The entire ring turns around the cathode while itself each spindle also rotates on its own axis, resulting in a so-called Orbital movement leads which requires that the several taps mounted around each spindle evenly exposed to the cathode become. Typically, the ring rotates several turns per minute while each spindle makes several revolutions per ring revolution. The Spindles are electrically isolated from the chamber and can be rotated Contacts provided so that during the Coating can be applied to the substrates.

The vacuum chamber is evacuated to a pressure of approximately 5 x 10 ^-3 millibars and heated to approximately 150 ° C.

The galvanized taps are then subjected to high-energy arc plasma cleaning, at which a (negative) bias of approximately 500 volts to the galvanized taps is created while an arc of approximately 500 amps hits the cathode and is held there. The Cleaning time is approximately five minutes.

It is introduced in an amount of argon gas that is sufficient to maintain a pressure of about 3 × 10 ^-2 millibar. Over a period of three minutes, a layer of zirconium with an average thickness of approximately 0.1016 µm [4 millionths (0.000004) inches] is applied to the chrome-plated taps. The cathodic arc comprises the supply of DC power to the cathode to cause a current flow of about 500 amps, the introduction of argon gas into the vessel to maintain the pressure in the vessel at about 1 x 10 ^-2 millibar, and Rotation of the taps in the manner described above in a circular motion.

After the zirconium layer is applied, the sandwich layer is applied to the zirconium layer. Nitrogen is regularly added to the vacuum chamber initiated while the arc discharge at approximately 500 amps persists. The flow rate of nitrogen will pulsed, d. h .. it changes regularly between a maximum flow rate, which is sufficient for the zirconium atoms arriving at the substrate Completely react to form zirconium nitride and a minimal one flow rate which is zero or a lower value that is insufficient, to complete react with all of the zirconium. The impulse of nitrogen lasts between one and two minutes (30 seconds to one minute on, then off). The total duration of the pulsed coating is approximately 15 minutes, being a sandwich layer with 10 to 15 layers of thickness of approximately each 0.0254 to 0.0381 µm [1 to 1.5 millionths of an inch] results. The material applied changes in the sandwich layer between completely reacted zirconium nitride and zirconium metal (or substoichiometric ZrN with a much lower nitrogen content).

After the sandwich layer is applied, becomes the flow rate of nitrogen for a duration of five up to ten minutes at their maximum value (which is sufficient to complete reacted zirconium nitride) to form the top of the sandwich layer to form a thicker "layer of paint". After this This zirconium nitride layer is applied for a long time from 30 seconds to a minute an additional stream of oxygen in a lot of about 0.1 standard liters per minute initiated, while the flow rates of Nitrogen and argon are kept at their previous values. A thin one Layer of mixed reaction products (zirconium oxynitride) with about a thickness 0.00508 to 0.0127 µm [0.2 to 0.5 millionths of an inch] is formed. At the end of this last one Coating phase, the arc is extinguished, the vacuum chamber is ventilated and the coated substrates are removed.

Claims (14)

A method of applying a multilayer coating to at least a portion of an object surface, comprising the steps of: applying by electroplating at least one electroplated layer to at least a portion of the object surface to form a galvanized object, and Exposing the galvanized article to a physical vapor deposition, characterized by the step of exposing the galvanized article having the at least one electroplated layer to pulse blow drying to dry the article prior to physical vapor deposition and to remove any liquid stains therefrom, the physical vapor deposition applying at least one layer selected from the group consisting of a refractory metal and a refractory metal alloy and at least one layer selected from the group consisting of a refractory metal compound and a refractory compound Metal alloy is comprised on at least a portion of the electroplated layer, the refractory metal compound being selected from the group consisting of nitrides, carbides, carbonitrides, oxides and Reaction products of the refractory metal, oxygen and nitrogen, and wherein the compound of the refractory metal alloy is selected from the group consisting of nitrides, carbides, carbonitrides, oxides and reaction products of the refractory metal alloy, oxygen and nitrogen. The method of claim 1, wherein the electroplating is the electroplating Making at least one layer selected from the group which consists of copper, nickel and chrome, on at least one Covered portion of the object surface. The method of claim 1, wherein the electroplating comprises: the galvanic production of at least one layer consisting of copper on at least a portion of the surface of the object by at least to provide an electroplated copper layer that electroplating at least one layer consisting of nickel on the at least one electroplated copper layer, to provide at least one electroplated nickel layer, and electroplating at least one made of chrome Layer on the at least one electroplated nickel layer, to provide at least one electroplated chrome layer. The method of claim 1, wherein the electroplating comprises: the electroplating at least one layer consisting of nickel on at least a portion of the surface of the object by at least to provide an electroplated nickel layer, and electroplating at least one made of chrome Layer on the at least one electroplated nickel layer, to provide at least one electroplated chrome layer. The method of claim 1, wherein the refractory metal and the heat-resistant Metal alloy are selected from the group consisting of zirconium, Titanium and a zirconium-titanium alloy. The method of claim 5, wherein there is a sandwich layer alternating layers of zirconium or a zirconium-titanium alloy and zirconium nitride or a nitride of a zirconium-titanium alloy by means of gas phase deposition on the layer of zirconium or a zirconium-titanium alloy is applied before the heat-resistant metal connection or the connection of a heat-resistant Metal alloy is applied. The method of claim 6, wherein a layer of zirconium nitride or a nitride of a zirconium-titanium alloy by means of vapor deposition is applied to the sandwich layer. The method of claim 7, wherein a layer of zirconia or zirconium-titanium oxide by means of vapor deposition on the layer made of zirconium nitride or a nitride of a zirconium-titanium alloy is applied. The method of claim 5, wherein a layer consisting of Zirconium nitride or a nitride of a zirconium-titanium alloy Vapor deposition on the layer of zirconium or a zirconium-titanium alloy is applied. The method of claim 9, wherein a layer consisting of Zirconium oxide or an oxide of a zirconium-titanium alloy by means of Vapor deposition on the zirconium nitride or a layer Nitride of a zirconium-titanium alloy is applied. A method according to claim 7 or 9, wherein there is a layer from the reaction products of zirconium or a zirconium-titanium alloy, oxygen and nitrogen by vapor deposition on the layer Zirconium nitride or a nitride of a zirconium-titanium alloy is applied. The method of claim 1, wherein the refractory metal compound and the refractory metal alloy compound are selected from the group consisting of zirconium nitride, zirconium oxide, reaction products of zirconium, acid material and nitrogen, titanium nitride, titanium oxide, reaction products of titanium, oxygen and nitrogen, a nitride of a zirconium-titanium alloy, an oxide of a zirconium-titanium alloy and reaction products of a zirconium-titanium alloy, oxygen and nitrogen. The method of claim 1, wherein the article is made of a material which is selected from the group consisting of a metal like zinc, a metal alloy like brass and plastic. The method of claim 1, wherein the object is around a tap, a door lock fitting or a lamp.